RESTORATIVE AGENTS. 41 



geonsly given in broken wind in the horse, in chronic 

 rheumatic disorders, chorea, and epilepsy. A very 

 convenient preparation, when the pure oil is undesir- 

 able, is made by shaking together in a bottle equal 

 volumes of cod-liver oil and lime water. For chronic 

 rough in the dog this last preparation two ounces, 

 und one ounce syrup of wild cherry bark ; give one to 

 two teaspoonfuls three to four times daily. 



Ferrum — Iron. 



Iron and its salts were the first mineral substances 

 used in medicine — now about three thousand years 

 ago — its chief function in the animal economy as 

 well as in nature being that of an oxygen carrier. 

 Iron is a normal constituent of the blood (1 part in 

 230 of red corpuscles) and tissues, where it exists as 

 an oxide in combination with the hematin of the 

 blood, and cannot exist in the blood without this. It 

 is also present in bile, lymph, chyle, in the pigment 

 of the eye, and in the gastric juice. Preparations of 

 iron should be given in small doses, as but a small 

 quantity is absorbed, and the rest is eliminated with 

 the fseces, which are blackened as the result of the 

 iron being transformed into a sulphide during its 

 passage through the intestinal canal. 



Chief Preparations and Their Doses. 



Ferrum Reductum — iron reduced by hydrogen. 

 This is a fine, grayish-black, lustreless powder, per- 

 manent in air, odorless, tasteless, and insoluble in 

 water or alcohol. Dose: H., 3ij.-iv. ; D., gr. i.-v. 



